Differentiation of right ventricular outflow tract-ventricular tachycardia (RVOT-VT) and arrhythmogenic right ventricular cardiomyopathy (ARVC) can be problematic in athletes. The high incidence of sudden death as the first clinical manifestation in ARVC highlights the importance of correct diagnosis and treatment. We report on the case of RVOT-VT in an elite female sprinter, and we review the literature on ventricular tachycardia (VT) in the absence of structural heart disease and ARVC.
Of patients who present with VT, 10% have no obvious structural disease. In the case of idiopathic VT from the RVOT and LVOT, the arrhythmia is monomorphic and generally not familial. In both disorders, the resting ECG has no identifiable abnormalities, and the echocardiogram and coronary angiography are usually normal. ARVC is a heart muscle disorder characterized by structural and functional abnormalities of the right ventricle due to a fibro-fatty replacement of the myocardium. The natural history of ARVC is considered to include four distinct phases. The early concealed phase of ARVC demonstrates ECG abnormalities concomitant to right and left ventricular dyskinesias. Differential diagnosis during this phase is problematic due to the presence of left bundle branch block morphology VT together with ECG anomalies commonly observed in athletes in RVOT-VT. Furthermore, long-standing VT in RVOT-VT may result in ventricular wall motion abnormalities mimicking ARVC. Radiofrequency ablation may be a valuable tool in the differential diagnosis, because this technique is highly effective in the treatment of RVOT-VT and of limited value in ARVC. Continued follow-up evaluation is an important for the confirmation of disease status after the diagnosis of idiopathic RVOT-VT.
1Research Institute for Sport and Exercise Science, Liverpool John Moores University, Liverpool, UNITED KINGDOM; 2CRY Centre for Sports Cardiology, Olympic Medical Institute, Northwick Park Hospital, Harrow, UNITED KINGDOM; 3Department of Cardiology, Northwick Park Hospital, Harrow, UNITED KINGDOM; 4Department of Cardiology, St. Mary's Hospital, London, UNITED KINGDOM; 5CMR Unit, The Royal Brompton Hospital, Sydney Street, London, UNITED KINGDOM; and 6Department of Cardiology, King's College Hospital, London, UNITED KINGDOM
Submitted for publication December 2007.
Accepted for publication February 2008.
Address for correspondence: Gregory P. Whyte, Ph.D., FACSM, Research Institute for Sport & Exercise Science, Liverpool John Moores University, Henry Cotton Campus, Truman Street, Liverpool, L3 2ET, United Kingdom; E-mail: firstname.lastname@example.org.